Thread: Dowel joining vs Mortise and tennoning

What sort of problems are you having with the M&T?

Dowels are a pain in the rear end. You really need some sort of jig to get the holes in the right place. You might be better off with a biscuit joiner. You should be able to pick one of the GMC ones up at Mitre 10. I've seen them in there. Otherwise you can definitely get one from Thrifty Link in Eden.

Mortise and Tenon is accepted to be the strongest joint bar none. We have 4000 year old mortice and tenon that date to the time of Pharos that are rock solid.

Dowel joints by nature are not weight bearing, because dowel is almost all end grain and has not binding glue strength. Dowels are also the product of commercial mass produced furniture, were speed of production is paramount, they have found less favor in craftsman's workshops.

However having said that, I am told that European craftsman tend to use them more then American/English/Australian craftsman.

There is a saying in boat-building: If it looks fair, it is fair.
So the question is - is fair is good enough or is fair only fair.

I am for M&T.

Mortice and tenon also open a world of joinery to you, and form the bases for larger and heaver construction. You can do whole projects in M&T. From the smallest draw to the apron and legs.

If you want to learn M&T then practice is the only way. Scrap hardwood, practice, and more practice. For tips I have found Taunton press very handy, they have a large section of articles on M&T.

It easy to join them for $4 for a month download their 1000'n articles as PDF's then simple do not renew at the end of the month.

Or just watch the free movies they have - will help.

My Tips: - sorry if some maybe obvious

• Clear and accurate marking - mark thrice and cut once
• Follow the 2/3 rule were the tenon is 2/3 the width of the mortise.
• Follow the 2/3 rule were the mortise is at least 2/3 the depth of the mortise timber
• Use a marking knife not a pencil
• Be conservative saw away from the line and slowly pair to it
• Have very sharp chisels and saws
• Gets some tips on pairing and mortising body postures
• Cut out the mortise first then fit the tenon to the mortice
• If the fit is to tight Mark the the tenon face with a pencil then slowly push into mortice and see were their is transference.
• If the Tenon does not fit trim the tenon, do not work/open the mortice
• If you make the tenon face to thin, you can glue on a shim to the tenon face
• Solid hand pressure should lock the joints into place
• Do not force together hardwood joints
• If the joint is still lose but otherwise acceptable look into drawboring
• A shoulder plane is handy in cleaning up the tenon.
• Do not repeatedly test fit M&T - it wears out the joint, crushes grain, etc etc, use dimensioned scrap instead
• Glue will swell up joints tighter, but glue is not a filer and will not glue to itself.

I hope that helps, but practice is the only teacher.

Originally Posted by gilbo

Has anyone got any tips for the mortising? Will dowel joints be strong enough for a kitchen island work bench (1100 mm x 600 mm)?

If you have a router, you can make a very simple jig that allows you to use it for mortising. Here's an example.

I also use dowel joints for more utilitarian pieces, for which I highly recommend the Ozziejig. Makes dowelling a breeze. A kitchen island made with good dowel joints should certainly be strong enough. I'd recommend a waterproof glue, e.g. polyurethane, such as Aquadhere Exterior.

I know there's plenty of furniture out there that has been put together with dowels, but I reckon they're terrible things. When they shrink, they take on an oval shape, which often breaks the glue bond, especially if the joint was a bit dry to start with. They're difficult to line up unless you have a decent jig and even then it's fiddly having to drill them one by one.

I just feel that these days we have several better ways, like biscuits or beadlock for example (or Domino if you have the cash to buy one). If you have a project that you feel needs dowels, then biscuits would be so much better a way to go, unless you're into 'authenticity'.

I know they still use dowels in kitchen carcases, but that's only because it's part of the 32mm system and they have line borers that take care of the drilling. It's geared up for mass production.

I'd still be interested to hear gilbo's problems with M&T. I'd also be interested in seeing the design for the island bench to see what would be a good alternative joinery system. I'm planning on starting one myself shortly and I'm still undecided on exactly how it's to be built: either plywood box with frame and panel sides or traditional frame and panel. But no bloody dowels!!

As an example, the joinery on my supplementary workbench is entirely ozziejig dowels. Another pic is here (second two attachments).

This thread shows the ozziejig used for doweling a set of shelves, and illustrates the accuracy that can be achieved.

There's no doubt, though, that M&Ts are stronger for frame construction.

I've always loved M&T joinery. It just has that feel about it that is old, I guess it appeals to the Neanderthal in me. It would be better in my opinion for you to describe the problems you have had, because it may be something that would give you grief even if you switched to dowels or biscuits.

I'm no expert woodworker, so you have to take my advice with a grain of salt, but I go about it in a fairly easy manner. I scribe the mortise lines first, and then use a Forstner bit to clear material. After that I go at with a set of chisels and square them up. And I keep my chisels razor sharp as well, so that I can just use hand pressure for the final trim.

I cut the tenons on my router table. I have a Woodpecker lift that moves in 1/64 increments (.4 mm) and that allows me to really sneak up on the fit. There's problems with going about it this way, and I will be the first to admit that. But it works good enough for me at the moment. Where I get into trouble is with long stock as the table won't support it easily.

It takes a while. Thats one of the problems with going at it that way. And I'm not confident enough to use this method and build a thru tenon. For me thats the holy grail. I love the look of thru tenons, and then keyed. But I've never built anything using thru tenons because I'm not certain I can pull it off.

These mortises were chopped using the method I described above:



I wanted the strength for this stand in case I get the urge someday to through a pair of monoblocks underneath. That means that bottom has to be good for 300 lbs, and hold it for years without bowing.





See those end panels? Those are biscuit joined to the legs, but the main strength is in those long members that are either M&T or trestle cut.

So I'll use a biscuit, but I'm actually starting to use them less and less. The reason I joined your forum was for the info you have on the Domino. I'm thinking about it, and I could probably use it. Haven't decided to do it yet though.

Thanks for the advise fellas. I think my problems may be with my chisels being a little under par for the job and I also may be trying to make my mortises too deep. I must get a Forstner bit or two and see if this helps me drill out the holes. Do Forstner bits have another name because my local Mitre 10 had no idea what I was asking for?

Originally Posted by gilbo

Do Forstner bits have another name because my local Mitre 10 had no idea what I was asking for?

- you answered your own question - its bunnings after all.

You need to be careful with pre-drilling - it can get messy. I found that I lost my ability to orient the direction of chisels making it hard to keep my cuts square with the sides. Ultimately it would be cheaper purchasing a single really good mortising chisel - ebay or 2nd hand market not bunnings, sharpening it - it is really not that hard, and it is fast 2 - 5 minutes per mortise. Rather then drilling the holes then fiddling with the chisels anyway to clean up the sides of the mortice.

A warning, a firmer chisel is not a morticing chisels, no matter what the manufacturer claims, this is more so true with Australian woods. Snap.

Best luck.

Do Forstner bits have another name because my local Mitre 10 had no idea what I was asking for?

Pambula Mitre 10 doesn't sell them. I bought mine from Timbecon. Carba-tec sell them as well. I have seen them once at Candelo market but that's a bit hit and miss.